Twisted willow - a potential problem... or not?

[user 44589]

Hi all, first post on here so treat me gently please

I have a Twisted Willow (Salix matsudana, 'Tortuosa') in my back garden that I fear may well turn into a big problem. It was planted by the previous owner of the house about 3 years ago and is currently standing about 12 feet tall with about a 10 foot spread (I did a bit of pruning last winter to maintain its shape) and it seems to be fairly happy where it is.
The tree is only about 6 -7 yards away from the corner of the house (concrete foundations and block walls) and I've only realised recently that it is almost directly over a sewer main (plastic pipe) which is probably about 4 feet below the level of the soil. I've been reading that willows can be very invasive and are very adept at locating water to the point of disrupting foundations, etc. I live in Northern Scotland where it's relatively temperate most of the year round, i.e. we get enough rain to keep it happy and me miserable . There also seems to quite a bit of conflicting information on the web as to how tall/big Twisted Willows can become.

So the questions that spring to mind are:
1. Is the house safe?
2. Is the sewer main likely to be safe?
3. If I need to remove the tree is it best to dig out all of the roots or just the main/central stump?

It's a beautiful small tree at the moment and I would really hate to have to remove it but if it's gonna cause problems in the future I'd much rather bite the bullet now. I look forward to reading your advice.
Cheers.

 

[rarefish383]

The root system reaches out about the same distance as the limbs, called the "drip line". I'm not familiar with how big this variety gets. By in large Willows are trees I like down on the lower 40 by a creek or pond. Some are very attractive. They tend to be a bit messy, constantly dropping dead wood. I know the roots used to play havoc on the old cast pipes, I'm not sure if they can get into PVC, but I would assume the larger pipe under ground would probably be cast. I'm sure some one with better knowledge will jump in shortly, Joe.

 

[S Mc]

Walrus, welcome to the site.

The first question I would like answered, if I were in your shoes, is to determine what type of soil is there. And not just is there clay involved but what KIND of clay. One of the biggest problems with structures is expansive soils. As they expand and shrink they create structural issues for foundations and such. This may well be a key factor in your decision. For example, if there is a high content of montmorillonite clay that would be a red flag. Because even if the soil is the primary culprit, the roots could exacerbate the problem with the expansive quality of this clay. If your clay is kaolinite, probably not so much.

Rarefish is correct in that a beautiful setting for a willow is out in the field or by the pond...out in the field. However, the Tortuosa does not typically get as big as many of the other species in this genus and, consequently, here in our area, make lovely landscape trees in small yards (gardens).

However, with that said, willows are probably at the bottom of the list of desirable trees to plant anywhere near a septic system. If the pipe develops a leak, the tree roots will find it. However, the depth of the pipe is a good thing. When you speak of a "sewer main" that brings to mind a 4 to 5" diameter high-density pipe connected to a city system rather than a private septic field. Is this correct?

Tree roots of deciduous trees can actually grow 2 to 3 times their canopy width. And with willow I would think the greater distance rather than the lesser.

 

[treeseer]

1. Is the house safe?

Yes, plenty of distance.

2. Is the sewer main likely to be safe?

Not so safe that you will sleep well as it matures

3. If I need to remove the tree is it best to dig out all of the roots or just the main/central stump?

Yes, it is best to dig out all the major roots, intact, and move the poor thing to a root-roomy spot.

It'd be nice if all utilities were located on title documents.

Roots can grow 10'+/year and go 5x branch spread (Magnolia)

 

[user 44589]

2. Is the sewer main likely to be safe?
Not so safe that you will sleep well as it matures
...

That's the one I am worried about the most. Although I said 'sewer main' I remember seeing the pipe when it was installed - it's a large-ish bore (about 2 1/2 foot) convoluted plastic pipe with a blue plastic liner. It provides a service to about 20 properties and I'm about half-way along the line. The thing that bothers me the most is that it has an inspection/access chamber and lid only about 2 yards from the tree; if the join between the pipe and chamber has got a bad seal or develops a leak then judging by what you gents have been saying the tree will do its damndest to get at the leak and possibly worm its way into the pipe/chamber. If it wasn't for the inspection/access chamber I think I'd be happy to leave it be but I think, rather sadly, that may settle it for me, it's gonna have to go .

Soil/clay - my house is built on what was, until 6 years ago, good fertile farm land: the general area is known traditionally as "The Bread-basket of the North" and the soil is a nice loamy type. I haven't got a clue what type of clay is underlying/within the topsoil.

Thanks for the replies people, you've been a great help.

 

[treeseer]

t at the leak and possibly worm its way into the pipe/chamber. If it wasn't for the inspection/access chamber I think I'd be happy to leave it be but I think, rather sadly, that may settle it for me, it's gonna have to go . :

Why not just dig it up and move it?

 

[S Mc]

Walrus, you could at least take a cutting from this tree if it is too big/expensive to transplant. They are super easy to root from stem cuttings.

This, of course, is presuming you have the room for it somewhere on your property.

Sylvia

 

[user 44589]

Much as I would love to replant it elsewhere in my garden unfortunately it is in just about the only place available which, I have no doubt, is why the original owner put it there: he just didn't appreciate what was underneath it.
I will ask around my friends and see if any of them would like it for their gardens, I know a few folk who have the free space and hopefully I won't have to destroy it.

 

[Loraxguy]

willow

I would take some cuttings off the tree and root them. And then past them out to your friends. Take the tree out and replace it with a large single stem shrub of some sort. It's small now so you can do the work of removal ten years from now it might cost you more..